Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing, excellent delayed fracture resistance, and high tensile shear stress after resistance spot welding by properly adjusting its chemical composition and its microstructure such that at least 20 Nb-based precipitates having a grain size of less than 0.10 m are present on average per 100 m.sup.2 of a cross section parallel to a thickness direction of the member, a prior austenite average grain size is 8 m or less, an average aspect ratio of prior austenite grains is 2.5 or less, and a volume fraction of martensite is 90% or more, and such that a standard deviation of Vickers hardness measured every 200 m on a surface of the member is 40 or less.

A steel with high hardness and excellent toughness contains, in mass %, 0.55-1.10% C, 0.10-2.00% Si, 0.10-2.00% Mn, 0.030% or less P, 0.030% or less S, 1.10-2.50% Cr, and 0.010-0.10% Al, with the balance consisting of Fe and unavoidable impurities. The structure of the steel after quenching is a dual phase structure of martensitic structure and spheroidized carbide. Spheroidized cementite particles with an aspect ratio of 1.5 or less constitute at least 90% of all cementite particles. The proportion of the number of spheroidized cementite particles on the prior austenite grain boundaries to a total number of cementite particles is 20% or less.

Provided are: a method for producing a high-speed tool steel material capable of increasing carbides in the structure of a high-speed tool steel product; a method for producing a high-speed tool steel product; and a high-speed tool steel product. The method for producing a high-speed tool steel material is provided with: a casting step for casting molten steel to obtain a steel ingot; a blooming step for heating the steel ingot obtained in said casting step to a temperature higher than 1120 C. and thereafter hot-working same to obtain an intermediate material; and a finishing step for heating the intermediate material obtained in the blooming step to a temperature of 900-1120 C. and thereafter hot-working same to obtain the high-speed tool steel material. Further, said method for producing a high-speed tool steel material is provided with an annealing step for annealing the high-speed tool steel material obtained in said finishing step. The present invention is also: a method for producing a high-speed tool steel product, wherein quenching and annealing is performed on the high-speed tool steel material obtained in the production method above; and a high-speed tool steel product.

Provided are: a method for producing a high-speed tool steel material capable of increasing carbides in the structure of a high-speed tool steel product; a method for producing a high-speed tool steel product; and a high-speed tool steel product. The method for producing a high-speed tool steel material is provided with: a casting step for casting molten steel to obtain a steel ingot; a blooming step for heating the steel ingot obtained in said casting step to a temperature higher than 1120 C. and thereafter hot-working same to obtain an intermediate material; and a finishing step for heating the intermediate material obtained in the blooming step to a temperature of 900-1120 C. and thereafter hot-working same to obtain the high-speed tool steel material. Further, said method for producing a high-speed tool steel material is provided with an annealing step for annealing the high-speed tool steel material obtained in said finishing step. The present invention is also: a method for producing a high-speed tool steel product, wherein quenching and annealing is performed on the high-speed tool steel material obtained in the production method above; and a high-speed tool steel product.

Provided is an abrasion-resistant steel including a predetermined chemical composition, in which content (mass %) of Mo and B satisfy MoB>0.0010, a mass fraction of Mo.sub.2FeB.sub.2 is from 0.0010 to 0.10%, an area ratio of martensite in a central portion in a thickness direction is 70% or more, Ceq obtained by the following (Formula 1) is 0.80% or less, and a plate thickness exceeds 50 mm;
Ceq=C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5(Formula 1) wherein, in (Formula 1), C, Mn, Cu, Ni, Cr, Mo, and V are contents (mass %) of each element.

Provided is an abrasion-resistant steel including a predetermined chemical composition, in which content (mass %) of Mo and B satisfy MoB>0.0010, a mass fraction of Mo.sub.2FeB.sub.2 is from 0.0010 to 0.10%, an area ratio of martensite in a central portion in a thickness direction is 70% or more, Ceq obtained by the following (Formula 1) is 0.80% or less, and a plate thickness exceeds 50 mm;
Ceq=C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5(Formula 1) wherein, in (Formula 1), C, Mn, Cu, Ni, Cr, Mo, and V are contents (mass %) of each element.

A hot-rolled steel sheet has a chemical composition that contains, in mass %, C, Si, Mn, P, S, Al, N and Ti, and that satisfies Formula (1); and a microstructure containing bainite and ferrite. In the interior of the steel sheet an average value of pole densities of an orientation group {100}<011> to {223}<110> is 4 or less, and a pole density of a {332}<113> crystal orientation is 4.8 or less. In an outer layer of the steel sheet, a pole density of a {110}<001> crystal orientation is 2.5 or more. Furthermore, among Ti carbo-nitrides in the steel sheet, the number density of fine Ti carbo-nitrides having a particle diameter of 10 nm or less is 1.010.sup.17 per cm.sup.3 or less, and a bake hardening amount is 15 MPa or more.

[Ti]48/14[N]48/32[S]0(1)

A hot-rolled steel sheet has a chemical composition that contains, in mass %, C, Si, Mn, P, S, Al, N and Ti, and that satisfies Formula (1); and a microstructure containing bainite and ferrite. In the interior of the steel sheet an average value of pole densities of an orientation group {100}<011> to {223}<110> is 4 or less, and a pole density of a {332}<113> crystal orientation is 4.8 or less. In an outer layer of the steel sheet, a pole density of a {110}<001> crystal orientation is 2.5 or more. Furthermore, among Ti carbo-nitrides in the steel sheet, the number density of fine Ti carbo-nitrides having a particle diameter of 10 nm or less is 1.010.sup.17 per cm.sup.3 or less, and a bake hardening amount is 15 MPa or more.

[Ti]48/14[N]48/32[S]0(1)

A metal alloy article having a combination of mechanical properties which are uniform across a cross-sectional area of the article is disclosed. The metal alloy is a precipitation hardenable alloy, such as an aluminum, copper, nickel, iron, or titanium alloy. In specific embodiments, the metal alloy is a copper-nickel-tin alloy with a nominal composition of Cu15Ni8Sn. The article is strengthened by process treatment steps including solution annealing, cold working, and precipitation hardening. The article has a constant cross-section along a length thereof with a minimum 0.2% offset yield strength of about 70 ksi.

A metal alloy article having a combination of mechanical properties which are uniform across a cross-sectional area of the article is disclosed. The metal alloy is a precipitation hardenable alloy, such as an aluminum, copper, nickel, iron, or titanium alloy. In specific embodiments, the metal alloy is a copper-nickel-tin alloy with a nominal composition of Cu15Ni8Sn. The article is strengthened by process treatment steps including solution annealing, cold working, and precipitation hardening. The article has a constant cross-section along a length thereof with a minimum 0.2% offset yield strength of about 70 ksi.